Exams › NEET › Physics
A rectangular coil of length 0.12 m and width 0.1 m having 50 turns of wire is suspended vertically in a uniform magnetic field of strength 0.2 weber/m². The coil carries a current of 2A. If the plane of the coil is inclined at an angle of 30° with the direction of the field, the torque required to keep the coil in stable equilibrium will be:
- 0.20 Nm
- 0.24 Nm
- 0.12 Nm
- 0.15 Nm
Correct answer: 0.24 Nm
Solution
The torque on a current-carrying coil in a magnetic field is given by τ = nIBA sinθ, where n is the number of turns, I is the current, B is the magnetic field, A is the area of the coil, and θ is the angle between the plane of the coil and the magnetic field. Here, n = 50, I = 2 A, B = 0.2 T, A = 0.12 × 0.1 = 0.012 m², and θ = 30°. Substituting, τ = 50 × 2 × 0.2 × 0.012 × sin(30°) = 0.24 Nm.
Related NEET Physics questions
- An alternating electric field, of frequency ν, is applied across the dees (radius = R) of a cyclotron that is being used to accelerate protons (mass = m). The operating magnetic field (B) used in the cyclotron and the kinetic energy (K) of the proton beam, produced by it, are given by:
- A proton carrying 1 MeV kinetic energy is moving in a circular path of radius R in uniform magnetic field. What should be the energy of an α-particle to describe a circle of same radius in the same field?
- A positively charged particle moving due east enters a region of uniform magnetic field directed vertically upwards. The particle will
- An electron enters a region where magnetic field (\( \vec{B} \)) and electric field (\( \vec{E} \)) are mutually perpendicular, then
- A \( 10 \, \text{eV} \) electron is circulating in a plane at right angles to a uniform field at magnetic induction \( 10^{-4} \, \text{Wb/m}^2 \) (\( = 1.0 \, \text{gauss} \)). The orbital radius of the electron is
- A uniform magnetic field acts at right angles to the direction of motion of an electron. As a result, the electron moves in a circular path of radius \( 2 \, \text{cm} \). If the speed of electron is doubled, then the radius of the circular path will be
⚔️ Practice NEET Physics free + battle 1v1 →